This invention relates to the synthesis of prostaglandins of the "one"-series. In particular it relates to a process of catalytic reduction where by the ease of preparation of said prostaglandins is greatly enhanced. The pharmaceutical uses of prostaglandins of the "one"-series in fertility control, bronchodilation, and blood pressure regulation is well known.
The recent synthesis of prostaglandin E.sub.1 in its optically active form constituted a notable achievement by E. J. Corey and his associates (J. Amer. Chem. Soc. 92, 2586 (1970); and references cited therein for other syntheses). This synthetic sequence is characterized by generally high-yield, stereocontrolled reactions. The selective reduction of the 11,15-bis-tetrahydropyranyl ether of prostaglandin F.sub.2 .sub..alpha., an essential step in the Corey synthesis, is, however, a notable exception as it is exceedingly sensitive to reaction conditions, capricious, and as it is not amenable to large-scale preparation. The improved synthesis presented herein obviates this troublesome step and thereby greatly enhances the synthesis of the prostaglandins of the "one"-series.